New Year's Eve weather fine for most

It's good news for New Year's Eve revellers in the North Island - the sun should be shining, but for those further south, celebrations might be a bit damper.

MetService forecaster Hordur Thordarson said the North Island would be "generally fine'' for the rest of the day and night.

"There might be the odd shower about the north-east corner - Gisborne, north of Hawkes Bay - this afternoon. But generally fine in the North Island, so a good evening for fire works and that sort of thing.''

An estimated 30,000 party-goers are in Gisborne for the annual Rhythm & Vines festival.

However, the South Island's West Coast and over the Southern Alps could become pretty sodden later today, and through into Wednesday, MetService chief forecaster Peter Kreft said.

"Over the next few days, rainfall totals on the South Island West Coast and over the Southern Alps may approach their one and two-day records,'' he said.

He warned campers near lakes and rivers in Canterbury and Otago that the water could rise rapidly.

It was also likely to be very windy down some valleys, he said.

The first day of 2013 would be a windy day in eastern areas from Southland through to Wairarapa and in Wellington.

"Around central New Zealand on Wednesday, the northwesterlies are likely to be particularly strong,'' Mr Kreft said.